9-Speed Planetary Gearbox

ABSTRACT

A transmission includes a drive shaft ( 1 ), an output shaft ( 2 ), a housing (G), a first planetary gear set (PR 1 ), a second planetary gear set (PR 2 ) and a third planetary gear set (PR 3 ), as well as six shift elements, comprising a first brake (B 1 ), a second brake (B 2 ), a first clutch (K 1 ), a second clutch (K 2,  K 2′ ), a third clutch (K 3,  K 3′,  K 3″ ) and a fourth clutch (K 4,  K 4′ ). The shift elements are selectively actuated, by which nine forward gears and one reverse gear are realized through different transmission ratio relationships between the drive shaft ( 1 ) and the output shaft ( 2 ). Each planetary gear set (PR 1,  PR 2,  PR 3 ) features a sun gear (S 1,  S 2,  S 3 ), a planetary gear, a planetary carrier (PT 1,  PT 2,  PT 3 ) and a ring gear (H 1,  H 2,  H 3 ). The drive shaft ( 1 ) and the output shaft ( 2 ) are arranged in a manner axially offset to each other and the drive shaft ( 1 ) is connectable to the ring gear (H 3 ) of the third planetary gear set (PR 3 ) and the second brake (B 2 ) through the first clutch (K 1 ). The ring gear (H 3 ) of the third planetary gear set (PR 3 ) and the second brake (B 2 ) are also connected to each other. A third shaft ( 3 ) is arranged coaxially to the drive shaft ( 1 ).

FIELD OF THE INVENTION

The present invention relates to a transmission, in particular for usein motor vehicles.

BACKGROUND

Here, a transmission in particular designates a multi-gear transmission,with which a predefined number of gears, thus fixed transmission ratiorelationships between transmission input and transmission output, isautomatically shiftable through shift elements. Here, the shift elementscomprise, for example, clutches or brakes.

DE 10 2008 032 015 discloses a powershift transmission with ten forwardgears and one reverse gear. Thereby, the powershift transmissionfeatures three planetary gear sets, which are able to be shifted witheach other in various combinations through six torque-transferringdevices, two of which are fixed connections and four of which areclutches. A torque is initiated through a start-up element in thepowershift transmission, and is transferred to an output element whiletaking into account the respective transmission ratio relationship.Thereby, the drive element and the output element are arranged coaxiallyto each other.

SUMMARY OF THE INVENTION

The present invention is subject to a task of proposing a transmissionof the aforementioned type, which features small gear steps with a largegear spread, which at the same type optimizes installation space and/orfeatures a high degree of efficiency. Additional objects and advantagesof the invention will be set forth in part in the following description,or may be obvious from the description, or may be learned throughpractice of the invention.

A “gear spread” is understood to mean the quotient from the transmissionratio relationship of the lowest gear and the transmission ratiorelationship of the highest gear, whereas the lowest gear features thelargest transmission ratio relationship, and the highest gear featuresthe smallest transmission ratio relationship. If there is a transmissionratio relationship of i<1.0, a transmission ratio into fast mode takesplace; that is, at the transmission output, a higher rotational speedthan that at the transmission input is applied.

In accordance with the invention, the tasks are solved with atransmission as described and claimed herein.

The transmission comprises a drive shaft, an output shaft, a housing, afirst planetary gear set, a second planetary gear set and a thirdplanetary gear set, along with six shift elements. It is particularlypreferable that, through the drive shaft, a torque or a rotationalmovement of a drive source, such as an internal combustion engine, isinitiated in the transmission. In a preferred manner, a start-upelement, such as a hydrodynamic torque converter or a fluid coupling, islocated between the drive source and the drive shaft.

In the following, a “shaft” is not solely understood as an exemplarycylindrical, rotatably mounted machine element for the transfer oftorques, but is also understood as a general connection element, whichconnects individual components or elements to each other, in particularconnection elements that connect several elements to each other in atorque-proof manner.

In particular, two elements are described as connected to each other ifthere is a fixed (in particular, a torque-proof) connection between theelements. In particular, such connected elements rotate with the samerotational speed.

Furthermore, two elements are described as connectable if there is adetachable connection between such elements. In particular, suchelements rotate with the same rotational speed if the connection exists.

The various components and elements of the specified invention may beconnected to each other through a shaft or a connection element, or alsodirectly, for example by means of a welded connection, crimpingconnection or another connection.

It is particularly preferable that the six shift elements comprise afirst brake, a second brake, a first clutch, a second clutch, a thirdclutch and a fourth clutch.

Thereby, clutches describe shift elements that, depending on theiroperating state, allow for a relative movement between two components orrepresent a connection for the transfer of a torque. A “relative motion”is understood as, for example, a rotation of two components, where therotational speed of the first component and the rotational speed of thesecond component differ from each other. In addition, the rotation ofonly one of the two rotatable components is conceivable, while the othercomponent is at a standstill or rotates in the opposite direction.

In the following, a “non-actuated clutch” is understood as an openclutch. This means that a relative motion between the two components ispossible. With an actuated or locked clutch, the two components rotateaccordingly with the same rotational speed and in the same direction.

A “brake” is understood as a shift element that is connected on one sideto a fixed element, such as a housing, and on another side to a rotatingelement. In the following, a “non-actuated brake” is understood as anopen brake. This means that the rotating component is in free-runningmode, which means that the brake preferably does not affect therotational speed of the rotating component. With an actuated or lockedbrake, a reduction in the rotational speed of the rotating component upto a stop takes place, which means that a connection between therotating element and the fixed element can be established. In thiscontext, “element” and “component” are equated.

As a general rule, the use of shift elements that are locked in anon-actuated state and open in an actuated state is also possible.Accordingly, the allocations between function and shifting state of theshifting states described above are understood in reverse order. Withthe following embodiments, an arrangement in which an actuated shiftelement is closed and a non-actuated shift element is open is initiallyused as the basis.

A planetary gear set comprises a sun gear, a planetary carrier and aring gear. Planetary gears that mesh with the toothing of the ring gearand/or with the toothing of the sun gear are rotatably mounted on theplanetary carrier.

In the following, a negative planetary gear set describes a planetarygear set with a planetary carrier on which the planetary gears arerotatably mounted, with one sun gear and one ring gear, whereas thetoothing of at least one of the planetary gears meshes with both thetoothing of the sun gear and with the toothing of the ring gear, bywhich the ring gear and the sun gear rotate in opposite directions, ifthe sun gear rotates with a fixed planetary carrier.

A positive planetary gear set differs from the negative planetary gearset just described in that the positive planetary gear set featuresinner and outer planetary gears, which are rotatably mounted on theplanetary carrier. Thereby, the toothing of the inner planetary gearsmeshes, on the one hand, with the toothing of the sun gear and, on theother hand, with the toothing of the outer planetary gears. The toothingof the outer planetary gears also meshes with the toothing of the ringgear. This has the consequence that, with a fixed planetary carrier, thering gear and the sun gear rotate in the same direction of rotation.

A particularly compact transmission can be realized through the use ofplanetary gear sets, by which a high degree of freedom in thearrangement of the transmission in the vehicle is achieved.

In particular, the sun gear, the ring gear, the planetary carrier andthe planetary gears of the planetary gear set are understood as elementsof a planetary gear set.

It is particularly preferable that the shift elements are able to beactuated selectively, thus individually and in line with demand, bywhich nine forward gears and one reverse gear can be realized throughdifferent transmission ratio relationships between the drive shaft andthe output shaft. Based on the numerous gears, it is possible to realizea fine gear shifting with a large gear spread, and thereby, for example,to operate the internal combustion engine in an optimal rotational speedrange, and thus efficiently. At the same time, this contributes toincreased driving comfort, since the internal combustion enginepreferably can be operated at a low rotational speed level. Thus, forexample, noise emissions that arise through the operation of theinternal combustion engine are reduced.

It is also preferable that the drive shaft and the output shaft arearranged in a manner axially offset to each other. This leads, forexample, to a particularly low need for axial installation space for thetransmission. Thereby, the transmission is suitable, in a particularlypreferable manner, for use in a vehicle with a front-transversearrangement of the drive train.

“Front-transverse arrangement of the drive train” is understood to meanthat the drive source, such as an internal combustion engine, isinstalled in the vehicle transverse to the direction of travel, andthat, preferably, the wheels of the front axle are drivable by the drivesource or the transmission.

It is particularly preferable that all elements of the first planetarygear set, the second planetary gear set and the third planetary gear setare rotatable. This means that there is no permanent connection betweenthe elements of the planetary gear sets and a fixed element, such as thehousing; rather, a connection can be selectively established through theactuation of the shift elements. This also advantageously contributes tothe fact that, by means of a low number of planetary gear sets, a highnumber of gears can be realized. Thereby, a blocking of the individualelements of the planetary gear sets can be produced only through theactuation of the respective shift elements.

It is also preferable that the drive shaft is, through the first clutch,connectable to the ring gear of the third planetary gear set and thesecond brake. It is also preferable that the ring gear of the thirdplanetary gear set and the second brake are also connected to eachother. This achieves a multitude of degrees of freedom with respect tothe planetary gear sets, such that a multitude of gears with the use ofrelatively few shift elements and planetary gear sets is feasible. It isalso preferable that a third shaft is arranged coaxially to the driveshaft.

The degree of efficiency of the transmission may be preferably increasedby the fact that, for the shift elements, energy is necessary for thechange to the shifting state, but not for maintaining the shifting stateitself. Here, actuated shift elements in line with demand, such aselectromechanical shift elements or electromagnetic shift elements, aresuitable in a particular way. Particularly when compared to conventionalhydraulically actuated shift elements, they are characterized by aparticularly low and efficient energy demand, since they can be operatednearly loss-free. In addition, with the solution specified above, it isadvantageous that permanently holding a control pressure for theactuation of the (for example) conventional hydraulic shift elements,and/or permanently applying the shift element in the shifted state withthe required hydraulic pressure, can be avoided. Thereby, additionalcomponents such as a hydraulic pump (for example) may be omitted, to theextent that they are solely used for the control and supply ofconventional hydraulically actuated shift elements. If the additionalcomponents are supplied with lubricant by the same hydraulic pump, andnot by a separate lubrication pump, at least this can be dimensionedsmaller. Moreover, any leaks at the oil transfer points of the hydrauliccircuit that may arise, particularly with rotating components, areeliminated. It is particularly preferable that this also contributes toincreased efficiency of the transmission in the form of a higher degreeof efficiency. Upon the use of actuated shift elements in line withdemand of the type specified above, it is particularly advantageous ifthey are accessible from the outside. Among other things, that has theadvantage that the required shifting energy can be easily fed to theshift elements. Therefore, the shift elements are, particularlypreferably, arranged so that they are easily accessible from theoutside. Within the meaning of the shift elements, “easily accessiblefrom the outside” means that no additional components are arrangedbetween the housing and the shift element, and/or that the shiftelements are, particularly preferably, arranged on the output shaft oron the drive shaft.

In an additional preferred form of the arrangement, the sun gear of thethird planetary gear set is connected to the first brake.

In a particularly preferable form of the arrangement, the transmissionfeatures a first spur pinion and a second spur pinion. At least each onespur gear of the first spur pinion and one spur gear of the second spurpinion are arranged coaxially to the drive shaft. By means of the firstspur pinion and/or the second spur pinion, a torque is transferablebetween the drive shaft and the output shaft, depending on the actuationof the shift elements. The use of spur pinions enables the transfer oftorque or rotational movements between the axially offset drive shaftand the output shaft, by which a particularly low need for axialinstallation space of the transmission in the vehicle arise. This is ofparticular importance for vehicles with a front-transverse arrangementof the drive train, since the available installation space in thevehicle for the drive source and the transmission is, in a particularmanner, limited by the width of the vehicle. However, other arrangementsof the drive train (for example, for rear-wheel drive vehicles and/orfor vehicles with a longitudinal arrangement of the drive train) areconceivable.

For a vehicle with a longitudinal arrangement of the drive train, thedrive source, such as an internal combustion engine, is preferablyinstalled in the vehicle longitudinally to the direction of travel, andthe wheels of the rear axle are preferably drivable by the drive sourceor the transmission.

A spur pinion comprises a single-stage or multi-stage spur gearbox withat least two spur gears, which mesh with each other. Thereby, therespective shafts and/or rotation axes of the spur gears are arrangedparallel to each other.

In an additional preferred form of the arrangement, the two spur pinionsare positioned in an axial alignment along the third shaft, particularlypreferably between the first planetary gear set and the third planetarygear set. Thereby, they are arranged in the order of first planetarygear set, first spur pinion, second spur pinion, third planetary gearset. This arrangement ensures a particularly space-saving design, sincethe individual planetary gear sets and shift elements can be easilynested in one another, and the various shafts, for example with thisarrangement, do not cross each other. To the extent that this allows forthe binding ability of the elements, a geometric positioning of theindividual gear sets, shift elements and spur pinions that deviates fromthe arrangement just described is conceivable, to the extent that thechange to the geometric positioning of the components occurs along thethird shaft.

“Binding ability” is understood to mean that, with a different geometricpositioning, thus an arrangement of components that deviates from thearrangement just described, the same binding or connection of theinterfaces is ensured, without the individual connection elements orshafts crossing each other.

Moreover, the use of a chain drive or a belt drive in place of the firstspur pinion and/or the second spur pinion is conceivable.

In an additional preferred embodiment, the first planetary gear set andthe second planetary gear set are axially positioned with respect to thethird shaft such that the second planetary gear set is arranged radiallyover the first planetary gear set. The arrangement of the secondplanetary gear set radially over the first planetary gear set ischaracterized, in a particular manner, by a particularly low need foraxial installation space. It is particularly preferable that the sungear of the second planetary gear set and the ring gear of the firstplanetary gear set are connected to each other. As an alternative tothis, a one-piece or a single-part version of the sun gear of the secondplanetary gear set and the ring gear of the first planetary gear set isconceivable. In this case, for example, the ring gear of the firstplanetary gear set possesses, in addition to an inner toothing, whichmeshes with the toothing of the planetary gears of the first planetarygear set, an outer toothing, which preferably assumes the function ofthe toothing of the sun gear of the second planetary gear set. Thereby,the outer toothing of the ring gear of the first planetary gear setmeshes with the toothing of the planetary gears of the second planetarygear set.

In an additional preferred form of the arrangement, each of the firstplanetary gear set, the second planetary gear set and the thirdplanetary gear set is designed as a negative planetary gear set. In aparticular manner, this arrangement on the one hand proves to be acost-effective option for realization of the gear set. On the otherhand, this arrangement features a high degree of efficiency with respectto the gear set, since, compared to positive planetary gear sets,negative planetary gear sets have an improved degree of efficiency.

To the extent allowed by the binding ability, as an alternativeembodiment, at least one negative planetary gear set may be convertedinto a positive planetary gear set. However, at the same time, thisrequires that the planetary carrier connection and the ring gearconnection are exchanged, and the amount of the stationary transmissionratio is increased by the value of 1.

Thereby, the stationary transmission ratio indicates the transmissionratio relationship between the sun gear and the ring gear, if theplanetary carrier is fixed.

In an additional preferred form of the arrangement, the drive shaft isconnectable to the planetary carrier of the first planetary gear setthrough the first clutch. It is also preferable that the drive shaft isconnectable to the sun gear of the first planetary gear set through thesecond clutch. It is also preferable that the drive shaft is connectableto the planetary carrier of the second planetary gear set through thethird clutch. The ring gear of the second planetary gear set ispreferably connected to a first spur pinion, and the first spur pinionis further connected to the output shaft. It is also preferable that theplanetary carrier of the third planetary gear set is connected to asecond spur pinion, the ring gear of the first planetary gear set andthe sun gear of the second planetary gear set. In addition, it is alsopreferable that the second spur pinion is further connectable to theoutput shaft through the fourth clutch. In this preferred arrangement,the first clutch, the second clutch and the third clutch are positionednext to each and in a coaxial arrangement at the drive shaft, and ineach case connected to the drive shaft on one side. Thereby, the firstclutch, the second clutch and the third clutch are positioned betweenthe transmission input and first planetary gear set along the thirdshaft, in the order of first clutch, second clutch, third clutch.Through this arrangement, the first clutch, the second clutch and thethird clutch are particularly easily accessible from the outside.

A transmission input thereby describes a location on a transmission atwhich, in driving mode, a torque is initiated by the drive source in thetransmission. In contrast to this, a “transmission output” is understoodto mean a location on the transmission at which the torque, taking intoaccount the corresponding transmission ratio relationships (for example,in a transfer case) is initiated or transferred to the drive shafts ofthe vehicle.

In an additional preferred variant of the transmission, the drive shaftof the first clutch and the second clutch is connectable to theplanetary carrier of the first planetary gear set. It is also preferablethat the drive shaft is connected to the sun gear of the first planetarygear set. The drive shaft is also preferably connected to the planetarycarrier of the second planetary gear set through the third clutch. It isalso preferable that the ring gear of the second planetary gear set isconnected to a first spur pinion, and the first spur pinion is furtherconnected to the output shaft. It is particularly preferable that theplanetary carrier of the third planetary gear set is connected to asecond spur pinion, the ring gear of the first planetary gear set andthe sun gear of the second planetary gear set. It is also preferablethat the second spur pinion is also connectable to the output shaftthrough the fourth clutch.

In an additional preferred form of the arrangement, the drive shaft isconnectable to the planetary carrier of the first planetary gear setthrough the first clutch. It is also preferable that the drive shaft isconnectable to the sun gear of the first planetary gear set through thesecond clutch. The drive shaft is preferably connected to the planetarycarrier of the second planetary gear set. Preferably, the ring gear ofthe second planetary gear set is connectable to a first spur pinionthrough the third clutch. The first spur pinion is preferably furtherconnected to the output shaft. The planetary carrier of the thirdplanetary gear set is preferably connected to a second spur pinion, thering gear of the first planetary gear set and the sun gear of the secondplanetary gear set. It is also preferable that the second spur pinion isalso connectable to the output shaft through the fourth clutch.

In an additional preferred arrangement of the transmission, the driveshaft is connectable to the planetary carrier of the first planetarygear set through the first clutch. It is also preferable that the driveshaft is connectable to the sun gear of the first planetary gear setthrough the second clutch. The drive shaft is preferably connected tothe planetary carrier of the second planetary gear set. It is alsopreferable that the ring gear of the second planetary gear set isconnected to a first spur pinion, whereas the first spur pinion ispreferably further connectable to the output shaft through the thirdclutch. The planetary carrier of the third planetary gear set ispreferably connected to a second spur pinion, the ring gear of the firstplanetary gear set and the sun gear of the second planetary gear set. Itis also preferable that the second spur pinion is connectable to theoutput shaft through the fourth clutch.

In an additional preferred variant of the transmission, the drive shaftis connectable to the planetary carrier of the first planetary gear setthrough the first clutch and the second clutch. It is also preferablethat the drive shaft is connected to the sun gear of the first planetarygear set. The drive shaft is preferably further connected to theplanetary carrier of the second planetary gear set. It is particularlypreferable that the ring gear of the second planetary gear set isconnectable to a first spur pinion through the third clutch, whereas thefirst spur pinion is preferably further connected to the output shaft.It is also preferable that the planetary carrier of the third planetarygear set is connected to a second spur pinion, the ring gear of thefirst planetary gear set and the sun gear of the second planetary gearset. The second spur pinion is preferably further connectable to theoutput shaft through the fourth clutch.

In an additional preferred form of the arrangement, the drive shaft isconnectable to planetary carrier of the first planetary gear set throughthe first clutch and the second clutch. It is also preferable that thedrive shaft is connected to the sun gear of the first planetary gearset. The drive shaft is preferably further connected to the planetarycarrier of the second planetary gear set. Preferably, the ring gear ofthe second planetary gear set is connected to a first spur pinion,whereas the first spur pinion is preferably further connectable to theoutput shaft through the third clutch. It is also preferable that theplanetary carrier of the third planetary gear set is connected to asecond spur pinion, the ring gear of the first planetary gear set andthe sun gear of the second planetary gear set. It is also preferablethat the second spur pinion is connectable to the output shaft throughthe fourth clutch.

In an additional preferred arrangement of the transmission, the driveshaft is connectable to the planetary carrier of the first planetarygear set through the first clutch. It is also preferable that the driveshaft is connectable to the sun gear of the first planetary gear setthrough the second clutch. The drive shaft is preferably connectable tothe planetary carrier of the second planetary gear set through the thirdclutch. It is also preferable that the ring gear of the second planetarygear set is connected to a first spur pinion. It is also preferable thatthe first spur pinion is connected to the output shaft. The planetarycarrier of the third planetary gear set is preferably connected to thering gear of the first planetary gear set and the sun gear of the secondplanetary gear set, and is connectable to a second spur pinion throughthe fourth clutch. Preferably, the second spur pinion is furtherconnected to the output shaft.

In a particularly preferable form of the arrangement, the first forwardgear can be represented by the locked first brake, the locked secondclutch and the locked fourth clutch. The second forward gear preferablycan be represented by the locked first brake, the locked first clutchand the locked fourth clutch. The third forward gear preferably can berepresented by the locked first clutch, the locked second clutch and thelocked fourth clutch. The fourth forward gear preferably can berepresented by the locked second clutch, the locked third clutch and thelocked fourth clutch or by the locked second brake, the locked thirdclutch and the locked fourth clutch or by the locked first brake, thelocked third clutch and the locked fourth clutch or by the locked firstclutch, the locked third clutch and the locked fourth clutch. The fifthforward gear preferably can be represented by the locked first clutch,the locked second clutch and the locked third clutch. The sixth forwardgear preferably can be represented by the locked first brake, the lockedfirst clutch and the locked third clutch. The seventh forward gearpreferably can be represented by the locked first brake, the lockedsecond clutch and the locked third clutch. The eighth forward gearpreferably can be represented by the locked first brake, the lockedsecond brake and the locked third clutch. The ninth forward gearpreferably can be represented by the locked second brake, the lockedsecond clutch and the locked third clutch. Particularly preferably, thereverse gear can be represented by the locked second brake, the lockedsecond clutch and the locked fourth clutch.

In accordance with an additional aspect of the present invention, amethod for operating the transmission is proposed. Thereby, at leastnine forward gears can be preferably selected in such a manner that, ineach gear, three shift elements are simultaneously locked. The remainingshift elements are preferably open. A gear change to an adjacent highergear or to an adjacent lower gear can be realized preferably by lockingat least one previously open shift element and by opening at least onepreviously locked shift element. Regardless of whether they are able tobe actuated hydraulically, electro-mechanically or in any other way,this leads to a lower need for energy of the shift elements, whichultimately has advantageous effects on consumption, for example theconsumption of fuel if an internal combustion engine is the drive sourceof the vehicle. In addition, particularly low shifting times can beobtained in this manner, which is also advantageous.

In principle, all shift elements can function in a frictional-locking orpositive-locking manner. It is particularly preferable that the fourthclutch is designed as a positive-locking shift element, in particular asa claw coupling. This leads to a significantly improved degree ofefficiency of the transmission, and thus significant consumptionadvantages with respect to fuel consumption, for example, for vehicleswith internal combustion engines.

In principle, on each shaft or each connection element, an electricmotor or another power/drive source may also be arranged.

In addition, at each shaft or each connection element, a freewheel mayin principle be arranged at the housing or at another shaft. As aresult, the corresponding shift element may be dimensioned smaller,since at least part of the torque is captured through the freewheel.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described more specifically by example on the basis ofthe attached figures. The following is shown:

FIG. 1 is a schematic view of a first preferred embodiment of atransmission in accordance with the invention;

FIG. 2 is a schematic view of a second preferred embodiment of atransmission in accordance with the invention;

FIG. 3 is a schematic view of a third preferred embodiment of atransmission in accordance with the invention;

FIG. 4 is a schematic view of a fourth preferred embodiment of atransmission in accordance with the invention;

FIG. 5 is a schematic view of a fifth preferred embodiment of atransmission in accordance with the invention;

FIG. 6 is a schematic view of a sixth preferred embodiment of atransmission in accordance with the invention;

FIG. 7 is a schematic view of a seventh preferred embodiment of atransmission in accordance with the invention; and

FIG. 8 is an exemplary shift diagram for a transmission in accordancewith FIGS. 1 to 7.

DETAILED DESCRIPTION

Reference will now be made to embodiments of the invention, one or moreexamples of which are shown in the drawings. Each embodiment is providedby way of explanation of the invention, and not as a limitation of theinvention. For example features illustrated or described as part of oneembodiment can be combined with another embodiment to yield stillanother embodiment. It is intended that the present invention includethese and other modifications and variations to the embodimentsdescribed herein.

In a schematic presentation, FIG. 1 shows a first preferred embodimentof the transmission, whereas the transmission comprises a firstplanetary gear set PR1, a second planetary gear set PR2, a thirdplanetary gear set PR3, a first spur pinion ST1, a second spur pinionST2 and six shift elements. All of the specified elements are arrangedin a housing G. The six shift elements comprise a first brake B1, asecond brake B2, a first clutch K1, a second clutch K2, a third clutchK3 and a fourth clutch K4. The first brake B1 and the second brake B2are firmly connected to the housing G on their one side. FIG. 1 alsoshows a drive shaft 1 and an output shaft 2, whereas the drive shaft 1and the output shaft 2 are arranged parallel to each other. On a firstside of the drive shaft 1, the drive shaft 1 has a free end. On thisfirst side of the drive shaft 1, a rotational movement or a torque isinitiated in the transmission. The drive shaft 1 is connectable to athird shaft through the first clutch K1. The third shaft 3 is furtherconnected to the planetary carrier PT1 of the first planetary gear setPR1, the ring gear H3 of the third planetary gear set PR3 and the secondbrake B2. In addition, the third shaft 3 connects the planetary carrierPT1 of the first planetary gear set PR1, the ring gear H3 of the thirdplanetary gear set PR3 and the second brake B2. The third shaft 3 runscoaxially to the drive shaft 1. The first clutch K1, the second clutchK2 and third clutch K3 are arranged coaxially to the third shaft 3 inthe order of first clutch K1, second clutch K2, third clutch K3, whereasthe first clutch K1 features a distance to the free end of the driveshaft 1 that is lower than that of the second clutch K2 or the thirdclutch K3. The first planetary gear set PR1, the second planetary gearset PR2, the third planetary gear set PR3, the first brake B1 and thesecond brake B2 are also arranged coaxially to the third shaft 3. Thesecond planetary gear set PR2 is arranged radially over the firstplanetary gear set PR1. The ring gear H1 of the first planetary gear setPR1 is connected to the sun gear S2 of the second planetary gear setPR2. The first planetary gear set PR1, the third planetary gear set PR3,the first brake B1 and the second brake B2 are arranged along the thirdshaft 3, beginning at the third clutch K3, in the order of firstplanetary gear set PR1, third planetary gear set PR3, first brake B1,second brake B2. The first spur pinion ST1 and the second spur pinionST2 are located between the first planetary gear set PR1 or the secondplanetary gear set PR2 and the third planetary gear set PR3, in theorder of first planetary gear set PR1 or second planetary gear set PR2,first spur pinion ST1, second spur pinion ST2, third planetary gear setPR3. At least one spur gear of the first spur pinion ST1 and the secondspur pinion ST2 are arranged coaxially to the third shaft 3. Through thefirst spur pinion ST1 and/or through the second spur pinion ST2, atransmission of torque or rotational movements takes place between thedrive shaft 1 and the output shaft 2. The output shaft 2 also has a freeend. Thereby, the free end of the drive shaft 1 and the free end of theoutput shaft 2 point in the same direction. The fourth clutch K4 isarranged coaxially to the output shaft 2 at the free end of the driveshaft 2, beginning at the fourth clutch K4. Thereby, the first spurpinion ST1, the second spur pinion ST2 and the fourth clutch K4 arearranged along the output shaft 2, in the order just specified. At leasteach one spur gear of the first spur pinion ST1 and one spur gear of thesecond spur pinion ST2 are arranged coaxially to the output shaft 2. Thedrive shaft 1 is further connectable to a fourth shaft 4 through thesecond clutch K2, whereas the fourth shaft 4 is further connected to thesun gear S1 of the first planetary gear set PR1. The drive shaft 1 isconnectable to a fifth shaft 5 through the third clutch K3, whereas thefifth shaft 5 is further connected to the planetary carrier PT2 of thesecond planetary gear set PR2. The ring gear H2 of the second planetarygear set PR2 is connected to the first spur pinion ST1 through a sixthshaft 6. The first spur pinion ST1 is further connected to the outputshaft 2. The sun gear S3 of the third planetary gear set PR3 isconnected to the first brake B1 through a seventh shaft 7. The planetarycarrier PT3 of the third planetary gear set PR3 is connected to aneighth shaft 8, whereas the eighth shaft 8 is further connected to thesecond spur pinion ST2, the ring gear H1 of the first planetary gear setPR1 and the sun gear S2 of the second planetary gear set PR2. Inaddition, the eighth shaft 8 connects the elements just specified amongeach other. The second spur pinion ST2 is further connected to a ninthshaft 9, whereas the ninth shaft 9 is connectable to the output shaft 2through the fourth clutch K4.

Each of the first planetary gear set PR1, the second planetary gear setPR2 and the third planetary gear set PR3 is designed as a negativeplanetary gear set. This means that planetary gears of the planetarycarrier PT1 mesh with the sun gear S1 and the ring gear H1 of the firstplanetary gear set PR1. The same applies for the second planetary gearset PR2 or the sun gear S2, the planetary carrier PT2 and the ring gearH2 of the second planetary gear set PR2, and for the third planetarygear set PR3 or the sun gear S3, the planetary carrier PT3 and the ringgear H3 of the third planetary gear set PR3.

Each of the first spur pinion ST1 and the second spur pinion ST2 isdesigned as a single-stage spur gearbox.

FIG. 2 shows an additional embodiment of the transmission described inFIG. 1, which differs from the embodiment described in FIG. 1 primarilyby a deviating positioning of the second clutch K2′. In the presentembodiment, the second clutch K2′ is positioned, in terms of space, in acoaxial arrangement to the third shaft 3 between the first planetarygear set PR1 and the first spur pinion ST1. This results in thefollowing changes with respect to the interfaces and connections in thetransmission. The drive shaft 1 is connectable to the third shaft 3through the first clutch K1. The third shaft 3 is also connected to thering gear H3 of the third planetary gear set PR3 and the second brakeB2. By way of derogation from the arrangement described in FIG. 1, thethird clutch 3 is also connectable to the fourth shaft 4 through thesecond clutch K2′, whereas the fourth shaft 4 is further connected tothe planetary carrier PT1 of the first planetary gear set PR1. Anadditional difference of the connection of the individual elements ofthe planetary gear sets PR1, PR2, PR3 consists of the fact that thedrive shaft 1 is now directly connected to the sun gear S1 of the firstplanetary gear set PR1. All additional interfaces and arrangements ofthe components correspond to the arrangement described in FIG. 1.

FIG. 3 shows a third variant of the transmission described in FIG. 1. Asignificant difference with the arrangement described in FIG. 1 consistsof the positioning of the third clutch K3′. Thereby, the third clutchK3′ is arranged coaxially to the third shaft 3 between the firstplanetary gear set PR1 or the second planetary gear set PR2 and thefirst spur pinion ST1. This has the consequence that the drive shaft 1is now directly connected to the planetary carrier PT2 of the secondplanetary gear set PR2. The ring gear H2 of the second planetary gearset PR2 is connected to the sixth shaft 6, whereas the sixth shaft 6 isnow connectable to the fifth shaft 5 through the third clutch K3′. Thefifth shaft 5 is further connected to the first spur pinion ST1, and thefirst spur pinion ST1 is further connected to the output shaft 2. Alladditional connections and interfaces, along with the arrangement of therespective components, correspond to the arrangement described in FIG.1.

FIG. 4 shows a fourth variant of the transmission described in FIG. 1.Thereby, the transmission corresponds to large extent to the embodimentdescribed in FIG. 1. A significant difference with the transmissiondescribed in FIG. 1 is reflected in the geometric position of the thirdclutch K3″. Thereby, the third clutch K3″ is arranged coaxially to theoutput shaft 2. Along the output shaft 2, the third clutch K3″, thefirst spur pinion ST1, the second spur pinion ST2 and the fourth clutchK4 are arranged in the specified order, beginning on the free end of theoutput shaft 2. Thereby, the third clutch K3″ and the fourth clutch K4are arranged coaxially to the output shaft 2. Thereby, at least one spurgear of the spur pinion ST1 and at least one spur gear of the secondspur pinion ST2 are also arranged coaxially to the output shaft 2. Here,in contrast to the embodiment described in FIG. 1, the planetary carrierPT2 of the second planetary gear set PR2 is directly connected to thedrive shaft 1. The ring gear H2 of the second planetary gear set PR2 isconnected to the sixth shaft 6, whereas the sixth shaft 6 is furtherconnected to the first spur pinion ST1. The first spur pinion ST1 isfurther connected to the fifth shaft 5, which is connectable to theoutput shaft 2 through the third clutch K3″. All additional connectionsand interfaces, along with the arrangement of the respective components,correspond to the arrangement described in FIG. 1.

FIG. 5 shows a fifth variant of the transmission described in FIG. 1.This differs from the variant described in FIG. 1 in that the secondclutch K2′ and the third clutch K3′ are arranged, in terms of space,coaxially to the third shaft 3 between the first planetary gear set PR1or the second planetary gear set PR2 and the first spur pinion ST1, inthe order of first planetary gear set PR1 or second planetary gear setPR2, second clutch K2′, third clutch K3′, first spur pinion ST1. Thisresults in changes with respect to interfaces or connections, asdescribed below. The drive shaft 1 is connectable to the third shaft 3through the first clutch K1. The third shaft 3 is further connectable tothe fourth shaft 4 through the second clutch K2′, whereas the fourthshaft 4 is further connected to the planetary carrier PT1 of the firstplanetary gear set PR1. Further, the drive shaft 1 is connected to thesun gear S1 of the first planetary gear set PR1 and the planetarycarrier PT2 of the second planetary gear set PR2. The ring gear H2 ofthe second planetary gear set PR2 is connected to the sixth shaft 6,whereas the sixth shaft 6 is connectable to the fifth shaft 5 throughthe third clutch K3′. The fifth shaft 5 is also connected to the firstspur pinion ST1, and the first spur pinion ST1 is further connected tothe output shaft 2. The embodiment shown in FIG. 5 arises from acombination of the embodiments of the alternative embodiments of thesecond clutch K2′ and the third clutch K3′ described in FIG. 2 and FIG.3.

FIG. 6 shows an additional embodiment of the transmission described inFIG. 1. By way of derogation from the arrangement described in FIG. 1,in the present embodiment, the second clutch K2′ is positioned, in termsof space, in a coaxial arrangement to the third shaft 3 between thefirst planetary gear set PR1 or the second planetary gear set PR2 andthe first spur pinion ST1. In addition, the third clutch K3″ is arrangedcoaxially to the output shaft 2, whereas the following elements arearranged along the output shaft 2, beginning at the free end of theoutput shaft 2, in the order of third clutch”, first spur pinion ST1,second spur pinion ST2, fourth clutch K4. The differences describedbelow with respect to the interfaces or connections of the individualelements arise from the specified changes to the positioning of thesecond clutch K2′ and the third clutch K3″. The drive shaft 1 isconnectable to the third shaft 3 through the first clutch K1, whereasthe third shaft 3 is further connectable to the fourth shaft 4 throughthe second clutch K2′, and the fourth shaft 4 is further connected tothe planetary carrier PT1 of the first planetary gear set PR1. The driveshaft 1 is further connected to the sun gear S1 of the first planetarygear set PR1 and the planetary carrier PT2 of the second planetary gearset PR2. The ring gear H2 of the second planetary gear set PR2 isconnected to the sixth shaft 6, whereas the sixth shaft 6 is furtherconnected to the first spur pinion ST1. The first spur pinion ST1 isfurther connected to the fifth shaft 5, whereas the fifth shaft 5 isconnectable to the output shaft 2 through the third clutch K3″. Alladditional connections and interfaces, along with the arrangement of therespective components, correspond to the arrangement described inFIG. 1. The embodiment of the transmission shown in FIG. 6 arises from acombination of the embodiments of the second clutch K2′ and the thirdclutch K3″ described in FIG. 2 and FIG. 4.

FIG. 7 shows an additional embodiment of the transmission described inFIG. 1. This differs from the arrangement described in FIG. 1 in thatthe fourth clutch K4′ is positioned, in terms of space, in a coaxialarrangement to the third shaft 3 between the second spur pinion ST2 andthe third planetary gear set PR3.Among other things, this leads to thefact that the output shaft 2 is free of shift elements. Differences withrespect to the interfaces, which are described below, arise from thepositioning of the fourth clutch K4′. The planetary carrier PT3 of thethird planetary gear set PR3 is connected to the ring gear H1 of thefirst planetary gear set PR1 and the sun gear S2 of the second planetarygear set PR2 through the eighth shaft 8. In addition, the eighth shaft 8is connectable to the ninth shaft 9 through the fourth clutch K4′. Theninth shaft 9 is further connected to the second spur pinion ST2, andthe second spur pinion ST2 is further connected to the output shaft 2.All additional connections and interfaces, along with the arrangement ofthe respective components, correspond to the arrangement described inFIG. 1.

In a table, FIG. 8 shows a shift matrix of the transmission inaccordance with the invention. By means of an X in the corresponding boxof the table, the shift element that is locked for the realization ofthe first to ninth forward gear and the reverse gear is made clear. Inaddition, three shifting alternatives for the fourth forward gear areindicated with the numbers 4-I, 4-II and 4-III.

The shifting states of the alternative embodiment of the second clutchK2′ are identical to the shifting states of the second clutch K2. Thesame applies to the shifting states of the alternative embodiment of thethird clutch K3′, K3″ and the shifting states of the third clutch K3,and/or the shifting states of the alternative embodiment of the fourthclutch K4′ and the shifting states of the fourth clutch K4. This meansthat, for example, the shifting states of the alternative embodiments ofthe third clutch K3′, K3″ are defined in the table, for example, throughthe shifting states of the third clutch K3.

Furthermore, the transmission ratio of the respective gear is specified,whereas the first forward gear features a transmission ratiorelationship of i=4.476, the second forward gear features a transmissionratio relationship of i=2.599, the third forward gear features atransmission ratio relationship of i=1.667, the fourth forward gearfeatures a transmission ratio relationship of i=1.267, the fifth forwardgear features a transmission ratio relationship of i=1.000, the sixthforward gear features a transmission ratio relationship of i=0.807, theseventh forward gear features a transmission ratio relationship ofi=0.705, the eighth forward gear features a transmission ratiorelationship of i=0.600 and the ninth forward gear features atransmission ratio relationship of i=0.501. Given the reversal ofdirection of the rotary movement, the reverse gear features a negativetransmission ratio relationship of i=−3.357. Here, “transmission ratio”and “transmission ratio relationship” are synonymous.

The corresponding gear jumps of the forward gears can also be derivedfrom the table. Under “gear jump,” the quotient of the transmissionratios of the lower forward gear and the adjacent higher forward gear isunderstood. Thereby, the gear jump from the first forward gear to thesecond forward gear features a value of φ=1.722, the gear jump from thesecond forward gear to the third forward gear features a value ofφ=1.559, the gear jump from the third forward gear to the fourth forwardgear features a value of φ=1.316, the gear jump from the fourth forwardgear to the fifth forward gear features a value of φ=1.267, the gearjump from the fifth forward gear to the sixth forward gear features avalue of φ=1.239, the gear jump from the sixth forward gear to theseventh forward gear features a value of φ=1.145, the gear jump from theseventh forward gear to the eighth forward gear features a value ofφ=1.175 and the gear jump from the eighth forward gear to the ninthforward gear features a value of φ=1.199.

The gear spread, as a quotient of the transmission ratio relationship ofthe lowest forward gear and the transmission ratio relationship of thehighest forward gear, is 8.942.

Modifications and variations can be made to the embodiments illustratedor described herein without departing from the scope and spirit of theinvention as set forth in the appended claims.

1-15. (canceled)
 16. A transmission for a motor vehicle, thetransmission comprising; a drive shaft (1); an output shaft (2); ahousing (G); a first planetary gear set (PR1), a second planetary gearset (PR2), and a third planetary gear set (PR3), wherein each planetarygear set (PR1, PR2, PR3) features a sun gear (S1, S2, S3), a planetarygear, a planetary carrier (PT1, PT2, PT3), and a ring gear (H1, H2, H3);six shift elements in the form of a first brake (B1), a second brake(B2), a first clutch (K1), a second clutch (K2, K2′), a third clutch(K3, K3′, K3″), and a fourth clutch (K4, K4′), wherein the shiftelements are selectively actuated, by which nine forward gears and onereverse gear are realized through different transmission ratiorelationships between the drive shaft (1) and the output shaft (2); thedrive shaft (1) and the output shaft (2) arranged in a manner axiallyoffset to each other; the drive shaft (1) connectable to the ring gear(H3) of the third planetary gear set (PR3) and the second brake (B2)through the first clutch (K1): the ring gear (H3) of the third planetarygear set (PR3) and the second brake (B2) also connected to each other;and a third shaft (3) arranged coaxially to the drive shaft (1).
 17. Thetransmission according to claim 16, wherein the sun gear (S3) of thethird planetary gear set (PR3) is connected to the first brake (B1). 18.The transmission according to claim 6, wherein a torque is transferablebetween the drive shaft (1) and the output shaft (2) through one or bothof a first spur pinion (ST1) and a second spur pinion (ST2).
 19. Thetransmission according to claim 18, wherein the first spur pinion (ST1)and the second spur pinion (ST2) are arranged in an axial alignmentalong the third shaft (3) between the first planetary gear set (PR1) andthe third planetary gear set (PR3), in the order of first planetary gearset (PR1), first spur pinion (ST1), second spur pinion (ST2), thirdplanetary gear set (PR3).
 20. The transmission according to claim 16,wherein the first planetary gear set (PR1) and the second planetary gearset (PR2) are axially positioned with respect to the third shaft (3)such that the second planetary gear set (PR2) is arranged radially overthe first planetary gear set (PR1) and the ring gear (H1) of the firstplanetary gear set (PR1) is connected to the sun gear (S2) of the secondplanetary gear set (PR2).
 21. The transmission according to claim 16,wherein each of the first planetary gear set (PR1), the second planetarygear set (PR2) and the third planetary gear set (PR3) is designed as anegative planetary gear set.
 22. The transmission according to claim 16,wherein: (a) the drive shaft (1) is connectable to the planetary carrier(PT1) of the first planetary gear set (PR1) through the first clutch(K1); (b) the drive shaft (1) is connectable to the sun gear (S1) of thefirst planetary gear set (PR1) through the second clutch (K2); (c) thedrive shaft (1) is connectable to the planetary carrier (PT2) of thesecond planetary gear set (PR2) through the third clutch (K3); (d) thering gear (H2) of the second planetary gear set (PR2) is connected to afirst spur pinion (ST1), and the first spur pinion (ST1) is furtherconnected to the output shaft (2); (e) the planetary carrier (PT3) ofthe third planetary gear set (PR3) is connected to a second spur pinion(ST2), the ring gear (H1) of the first planetary gear set (PR1) and thesun gear (S2) of the second planetary gear set (PR2); and (f) the secondspur pinion (ST2) is further connectable to the output shaft (2) throughthe fourth clutch (K4).
 23. The transmission according to claim 16,wherein: (a) the drive shaft (1) of the first clutch (K1) and the secondclutch (K2′) is connectable to the planetary carrier (PT1) of the firstplanetary gear set (PR1); (b) the drive shaft (1) is connected to thesun gear (S1) of the first planetary gear set (PR1); (c) the drive shaft(1) connected to the planetary carrier (PT2) of the second planetarygear set (PR2) through the third clutch (K3); (d) the ring gear (H2) ofthe second planetary gear set (PR2) is connected to a first spur pinion(ST1); (e) the first spur pinion (ST1) is further connected to theoutput shaft (2); (f) the planetary carrier (PT3) of the third planetarygear set (PR3) is connected to a second spur pinion (ST2), the ring gear(H1) of the first planetary gear set (PR1) and the sun gear (S2) of thesecond planetary gear set (PR2); and (g) the second spur pinion (ST2) isalso connectable to the output shaft (2) through the fourth clutch (K4).24. The transmission according to claim 16, wherein: (a) the drive shaft(1) is connectable to the planetary carrier (PT1) of the first planetarygear set (PR1) through the first clutch (K1); (b) the drive shaft (1) isconnectable to the sun gear (S1) of the first planetary gear set (PR1)through the second clutch (K2); (c) the drive shaft (1) is connected tothe planetary carrier (PT2) of the second planetary gear set (PR2); (d)the ring gear (H2) of the second planetary gear set (PR2) is connectableto a first spur pinion (ST1) through the third clutch (K3′), whereas thefirst spur pinion (ST1) is further connected to the output shaft (2);(e) the planetary carrier (PT3) of the third planetary gear set (PR3) isconnected to a second spur pinion (ST2), the ring gear (H1) of the firstplanetary gear set (PR1) and the sun gear (52) of the second planetarygear set (PR2); and (f) the second spur pinion (ST2) is also connectableto the output shaft (2) through the fourth clutch (K4).
 25. Thetransmission according to claim 16, wherein: (a) the drive shaft (1) isconnectable to the planetary carrier (PT1) of the first planetary gearset (PR1) through the first clutch (K1); (b) the drive shaft isconnectable to the sun gear (S1) of the first planetary gear set (PR1)through the second clutch (K2); (c) the drive shaft (1) is connected tothe planetary carrier (PT2) of the second planetary gear set (PR2); (d)the ring gear (H2) of the second planetary gear set (PR2) is connectedto a first spur pinion (ST1), whereas the first spur pinion (ST1) isfurther connectable to the output shaft (2) through the third clutch(K3″); (e) the planetary carrier (PT3) of the third planetary gear set(PR3) is connected to a second spur pinion (ST2), the ring gear (H1) ofthe first planetary gear set (PR1) and the sun gear (S2) of the secondplanetary gear set (PR2); and (f) the second spur pinion (ST2) isfurther connectable to the output shaft (2) through the fourth clutch(K4).
 26. The transmission according to claim 16, wherein: (a) the driveshaft (1) is connectable to the planetary carrier (PT1) of the firstplanetary gear set (PR1) through the first clutch (K1) and the secondclutch (K2′); (b) the drive shaft (1) is connected to the sun gear (S1)of the first planetary gear set (PR1); (c) the drive shaft (1) isconnected to the planetary carrier (PT2) of the second planetary gearset (PR2); (d) the ring gear (H2) of the second planetary gear set (PR2)is connectable to a first spur pinion (ST1) through the third clutch(K3′), whereas the first spur pinion (ST1) is further connected to theoutput shaft (2); (e) the planetary carrier (PT3) of the third planetarygear set (PR3) is connected to a second spur pinion (ST2), the ring gear(H1) of the first planetary gear set (PR1) and the sun gear (S2) of thesecond planetary gear set (PR2); and (g) the second spur pinion (ST2) isfurther connectable to the output shaft (2) through the fourth clutch(K4).
 27. The transmission according claim 16, wherein: (a) the driveshaft (1) is connectable to planetary carrier (PT1) of the firstplanetary gear set (PR1) through the first clutch (K1) and the secondclutch (K2′); (b) the drive shaft (1) is connected to the sun gear (S1)of the first planetary gear set (PR1); (c) the drive shaft (I) isconnected to the planetary carrier (PT2) of the second planetary gearset (PR2); (d) the ring gear (H2) the second planetary gear set (PR2) isconnected to a first spur pinion (ST1), whereas the first spur pinion(ST1) is further connectable to the output shaft (2) through the thirdclutch (K3″); (e) the planetary carrier (PT3) of the third planetarygear set (PR3) is connected to a second spur pinion (ST2), the ring gear(HI) of the first planetary gear set (PR1) and the sun gear (S2) of thesecond planetary gear set (PR2); and (f) the second spur pinion (ST2) isconnectable to the output shaft (2) through the fourth clutch (K4). 28.The transmission according to claim 16, wherein: (a) the drive shaft (1)is connectable to the planetary carrier (PT1) of the first planetarygear set (PR1) through the first clutch (K1); (b) the drive shaft (1) isconnectable to the sun gear (SI) of the first planetary gear set (PR1)through the second clutch (K2); (c) the drive shaft (1) is connectableto the planetary carrier (PT2) of the second planetary gear set (PR2)through the third clutch (K3); (d) the ring gear (H2) of the secondplanetary gear set (PR2) is connected to a first spur pinion (ST1),whereas the first spur pinion (ST1) is connected to the drive shaft (2);(e) the planetary carrier (PT3) of the third planetary gear set (PR3) isconnected to the ring gear (H1) of the first planetary gear set (PR1)and the sun gear (S2) of the second planetary gear set (PR2), and isconnectable to a second spur pinion (ST2) through the fourth clutch(K4′); and (f) the second spur pinion (ST2) is further connected to theoutput shaft (2).
 29. The transmission according to claim 16, wherein:(a) the first forward gear is represented by the locked first brake(B1), the locked second clutch (K2, K2′) and the locked fourth clutch(K4, K4′); (b) the second forward gear is represented by the lockedfirst brake (B1), the locked first clutch (K1) and the locked fourthclutch (K4, K4′); (c) the third forward gear can be represented by thelocked first clutch (K1), the locked second clutch (K2, K2′) and thelocked fourth clutch (K4, K4′); (d) the fourth forward gear can berepresented by one of: (1) the locked second clutch (K2, K2′), thelocked third clutch (K3, K3′, K3″) and the locked fourth clutch (K4,K4′) (2) the locked second brake (B2), the locked third clutch (K3, K3′,K3″) and the locked fourth clutch (K4, K4′) (3) the locked first brake(B1), the locked third clutch (K3, K3′, K3″) and the locked fourthclutch (K4, K4′) (4) the locked first clutch (K1), the locked thirdclutch (K3, K3′, K3″) and the locked fourth clutch (K4, K4′); (e) thefifth forward gear is represented by the locked first clutch (K1), thelocked second clutch (K2, K2″) and the locked third clutch (K3, K3′,K3″); (f) the sixth forward gear is represented by the locked firstbrake (B1), the locked first clutch (K1) and the locked third clutch(K3, K3′, K3″); (g) the seventh forward gear is represented by thelocked first brake (B1), the locked second clutch (K2, K2′) and thelocked third clutch (K3, K3′, K3″); (h) the eighth forward gear isrepresented by the locked first brake (B1), the locked second brake (B2)and the locked third clutch (K3, K3′, K3″); (i) the ninth forward gearis represented by the locked second brake (B2), the locked second clutch(K2, K2′) and the locked third clutch (K3, K3′, K3″); and (j) thereverse gear is represented by the locked second brake (B2), the lockedsecond clutch (K2, K2′) and the locked fourth clutch (K4, K4′).
 30. Amethod for operating the transmission according to claim 1, comprisingselecting each of the nine forward gears in such a manner that, in eachgear, three shift elements are locked and the remaining shift elementsare open, and for a gear change to an adjacent higher gear or to anadjacent lower gear, locking at least one previously open shift elementand opening at least one previously locked shift element.